During the curing cycle of a tire manufacturing process, air may become trapped between a green tire and a mold cavity when a tire molding press is closed. This trapped air can cause “lightness” in the cured tire. One known method for evacuating this trapped air is through the use of vents. Vents are added in the mold and bead rings to bleed the air during the curing process. The vents are either directly drilled through the mold or bead rings, or a hole is drilled through the mold or bead ring and a preformed insert is placed in the hole, thereby forming a vent.
During air evacuation, the elastomeric tire material may flow into the vents, creating projections on the surface of the tire known as sprues. Known prior art vents have employed smaller diameters, through the body of an insert or the mold, which still results in conspicuous sprue formation.